( xxvii ) 



species emerge normally in May or earlier, and the larvae 

 attempt in Great Britain to follow out their natural habit, 

 with the result that the great majority must perish, especially 

 in the case of edusa. 



Mr. B. S. Standen exhibited specimens of Lycwna dolus, 

 the type from Bordighera, and also Pieris brassicse with 

 greenish .under wings, a common form in the neighbourhood 

 of Florence. 



Mr. C. P. Pickett exhibited pupa-cases of Saturnia pavcmia, 

 one with two openings, one with no openings, and a third con- 

 taining three pnpie, from one only of which the imago had 

 emerged. Mr. J. W. Tutt said that this phenomenon was not 

 unusual in the case of silkworms, and commonly occurred also 

 in the case of artificially bred Lasiocampa lanestris, being 

 probably due to overcrowding, but he did not know that there 

 was any evidence how the work was done. 



The Rev. A. E. Eaton exhibited adult Pst/chodidai of morpho- 

 logical interest, preserved in corked tubes with 2% Formic 

 Aldehyde in distilled water. 



(1) Perlcoma notabilis, Etn., as a sample of male flies 

 retaining prothoracic air-nipples, such as Curtis figured [Brit. 

 Ent., xvi, 745 (1839)], and are possessed by pupa? of both 

 sexes, illustrated both by Mial and Walker and by Fritz 

 Miiller in the volume of the Transactions of this Society 

 for 1805; also by Kellogg, Ent. News xii, 48, figs, a, b 

 (Feb. 1901). Perlcoma soleata, Hal. MS., has similar sin dl 

 claviform air-nipples on the prothorax ; and so have some 

 undescribed species more nearly related to P. notabilis, natives 

 of middle Europe or of Algeria. 



(2) Male flies possessing erectile sacs, or else protrusible 

 tentacles arising one on each side of the mesothorax near 

 the spiracle, and receiving a strong branch from the main 

 trachea of each side. In the state of contraction these sacs 

 or tentacles resemble a tuft of hair, which is very dense in 

 some flies : by their distension, the tufts are either spread open, 

 or the tuft is resolved into scattered hairs distributed over 

 at least the whole of the upper surface of the tentacle. 

 These organs are probably subservient to sexual attraction, 

 and perhaps secrete scent. A few males possess them in 



